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Catalyst 3560 Switch Software Configuration Guide
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Chapter 38 Configuring IPv6 MLD Snooping
Configuring IPv6 MLD Snooping
MLD Snooping Configuration Guidelines
When configuring MLD snooping, consider these guidelines:
You can configure MLD snooping characteristics at any time, but you must globally enable MLD
snooping by using the ipv6 mld snooping global configuration command for the configuration to
take effect.
When the IPv6 multicast router is a Catalyst 6500 switch and you are using extended VLANs (in the
range 1006 to 4094), IPv6 MLD snooping must be enabled on the extended VLAN on the Catalyst
6500 switch in order for the Catalyst 3560 switch to receive queries on the VLAN. For normal-range
VLANs (1 to 1005), it is not necessary to enable IPv6 MLD snooping on the VLAN on the Catalyst
6500 switch.
MLD snooping and IGMP snooping act independently of each other. You can enable both features
at the same time on the switch.
The maximum number of multicast entries allowed on the switch is determined by the configured
SDM template.
The maximum number of address entries allowed for the switch is 1000.
Enabling or Disabling MLD Snooping
By default, IPv6 MLD snooping is globally disabled on the switch and enabled on all VLANs. When
MLD snooping is globally disabled, it is also disabled on all VLANs. When you globally enable MLD
snooping, the VLAN configuration overrides the global configuration. That is, MLD snooping is enabled
only on VLAN interfaces in the default state (enabled).
You can enable and disable MLD snooping on a per-VLAN basis or for a range of VLANs, but if you
globally disable MLD snooping, it is disabled in all VLANs. If global snooping is enabled, you can
enable or disable VLAN snooping.
Beginning in privileged EXEC mode, follow these steps to globally enable MLD snooping on the switch:
To globally disable MLD snooping on the switch, use the no ipv6 mld snooping global configuration
command.
Beginning in privileged EXEC mode, follow these steps to enable MLD snooping on a VLAN.
Note When the IPv6 multicast router is a Catalyst 6500 switch and you are using extended VLANs (in the
range 1006 to 4094), IPv6 MLD snooping must be enabled on the extended VLAN on the Catalyst 6500
switch in order for the Catalyst 3560 switch to receive queries on the VLAN. For normal-range VLANs
(1 to 1005), it is not necessary to enable IPv6 MLD snooping on the VLAN on the Catalyst 6500 switch.
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 ipv6 mld snooping Globally enable MLD snooping on the switch.
Step 3 end Return to privileged EXEC mode.
Step 4 copy running-config startup-config (Optional) Save your entries in the configuration file.
Step 5 reload Reload the operating system.